Controlled fractional distillation apparatus



Sept. 25, 1945.

CONTROLLED FRAGTI ONAL DISTILLATION APPARATUS Condenser R. BURK 2,385,345

Filed Sept. 25, 1942 8 l2 .4' A l2 8 5 35 Heotexchon er 3 2 t "01/ J g l Column filler 2O 1 1 5- I z m I 26 L 1 k; Temperature conditioner v INVENTOR. ROBERT E.BURK

ATTORNEYS Patented Sept. 25, 1945 CONTROLLED FRACTIONAL D ISTILLATION APPARATUS Robert E. Burk, Cleveland Heights, Ohio, assignor to The Standard Oil Company, Cleveland, Ohio, a corporation of Ohio Application September 25, 1942, Serial No. 459,613

5 Claims.

This invention relates to fractional distillation, and it is among the objects of the invention to provide construction which makes possible a highly precise control of the fractionating action, and with particular freedom from unwanted interference by external temperature changes. Other objects and advantages will appear from the following description.

To the accomplishment of the foregoing and related ends; the invention, then, comprises the features hereinafter fully described, and particularly pointed out in the claims, ,the following description and the annexed drawin setting forth in detail certain illustrative embodiments of the invention, these being indicative however, of but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawing:

Fig. 1 is a semi-diagrammatic elevational view of apparatus in accordance with the invention; and Figs. 2 and 3 are vertical and transverse sections, on large scale, and partly broken away on account of space limitations.

The column comprises a container 2, of height and diameter in accordance with the particular duty in view, according to whether for large or small size scale operations, and sufficient thickness or strength with respect to whether pressure is to be employed or; not. Secured to the. container are top and bottom headers 3, 4, and spaced within the container is a liner 5 which forms a central compartment C and an.outer space J thereabout and between the liner and the container wall 2. The central compartment C contain suitable filler for providing extended surface for liquid and vapor contact, and such filler may be of any usual or preferred kind, as for instance multitudinous vertical surfaces, tower rings, etc., desirably the filler being of a form to provide highest efliciency of liquid and vapor contact. At the lower part of the tower a feed inlet connection 1 introduces the supply of material which is to be fractionated, and the vapor connection 8 on the top leads to the condenser 9 which has further connections l fOr a vent and I I for discharge of condensed product. A reflux connection l2 also leads from the condenser back to discharge in the top of the column.

ture control means throughout the fractionating zone, by the space J between the container wall 2 and the liner wall 5. This space is supplied with a temperature control fluid which is circulated from the bottom to the top, by any suitable means, such as pump l5. Special uniformity is bad in distribution by arranging a manifold IS in circular form, branches ll therefrom leading into the container 2 to discharge into the 10 space J, the number of branches in any given instance depending upon the size of the column and the rate of circulation desired. At the top of the column a similar circular manifold 20, having branches 2| collects the circulated fluid l5 and returns it to a temperature conditioner 23, which applies heat or cold as predetermined. If in any particular instance it is desired to make the direction of flow first to the top, the piping arrangement of course may permit such usage. It is usually desirable to provide a valve-controlled by-pass 26 around the temperature conditioner, for use where it is desired to pass at least some of the fluid around the temperature conditioner. A flow meter 28 assists in accuracy of maintenance of conditions. The temperature control fluid which is circulated thus through the column and usually in counter-direction to the flow of the reflux condensate, will be ,chosen in any instance in accordance with the temperature conditions required by the material which is being fractionally distilled. Water is most generally useful, but the arrangement allows application of steam, heavy liquids, etc, the temperature conditioner 23 being provided with temperature control means, such for instance as a steam heating coil, electric heater, or if desired a cooling coil, etc., and such coils or the like are further desirably equipped with thermoregulating means of usual or preferred form. -1 From the construction so far described, it is seen that in operation the material to be fractionated is supplied through feed-connection 'l to the lower end of the tower, and vapors rising come into contact in countef current flow with the reflux condensate which is supplied by connection I2 at the top of the tower, and thus a free interchange of molecules and sorting out, and segregation goes forward with progressive cooling up through the column, while at the same time an effective super-control of the temperature gradient is applied by the temperature controlling fluid flowing up in counter direction to the reflux. And the temperature gradient in the space J is precisely conditioned by the speed of flow. Thus, by regulation of the rate of pumping, the temperature gradient applied by means of the fluid-control space J may be adjusted as desired in any instance, from one extreme condition in which on account of the rapid flow substantially no temperature drop is applied from bottom to top, through the range of progressive temperature gradients, to a further extreme in which by very slow circulation a maximum temperature drop is imposed from bottom to top. It is thus seen that control of the velocity of flow of the. temperature conditioning fluid gives a means of precise adjusting of the temperature gradient throughout the fractionatingzone, such as has not been at all possible with ordinary fractionating equipment. And, further, by control of the temperature conditioner 23, the general temperature level, whether low or high, can be set and maintained with precision.

As a further refinement, in order to guard the column and the temperature control system against untoward effects of possible outside temperature fluctuation, I provide a special lagging or heat-insulation 30, and in association a special reinforcing framing which guards the entire apparatus, subjected as it is to considerable stresses from the expansion and contraction differentials involved in temperature differences which may be quite large and affecting a considerable expanse of metal elements. The auxiliary or reinforcing framing outside thus is of importance in an aspect of column construction which is ordinarily weak. As auxiliary framing, the top and bottom headers 3, 4, may be of sumcient size to have longitudinal reinforcing elements 32 secured therebetween. These may be of structural steel forms, as for instance channels or the like. In the framing, the lagging 30 about the container wall 2 thus in a protected position, the

number of reinforcing or framing elements 32 being as desired in any given case, in accordance with the size of the column; and the lagging may be further covered with sheet metal 34. At the top, the opening in the header 3 is covered by a closure element 35, suitably secured, and through which the vapor connection 8 and the reflux connection i2 pass; and heat insulation 36, further surrounds the connections and I2 and guards the top against undesired abrupt heat loss.

In operation, mixed material to be fractionated is supplied to the column through the feed inlet 1, and vapors rising through the column proceed. toward the condenser 9. Reflux condensate from the latter flows downwardly, preferably through a heat-exchanger 2%, to the top of the column, and thence downwardly in counter-flow to the rising vapors and in contact therewith. The over-all temperature control is applied from the temperature conditioner 28, the control fiuid circulating through the space J between the liner and the container wall. Usually, the direction of circulation of this fluid is the same as that of the vapors. In some cases however, it may be desired to flow the fiuid'in the other direction. In operating in continuous manner, the supply of material to be fractionated may be provided indefinitely, and the temperature control likewise may be maintained in continuous operation. In instances where it is desired to operate batchwise, and cuts or fractions of different boiling point are to be taken off, a temperature-conditioning fluid can be applied as an abrupt temperature-change means for changing the temperature for the particular out or fraction des1re Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any" of the following claims, or the equivalent of such, be employed.

I therefore particularly point out and distinctly claim as'my invention:

1. A fractional distillation apparatus, comprising a container, top and bottom headers therefor, a liner spaced within the container and forming a. central compartment, surface-providing filler means for liquid and vapor contact within the central compartment, a feed inlet-to the central compartment below for material to be fractionated, and an outlet abovefor vapors, a connection for returning condensate from the condenser to the top of the central compartment, an insulating closure at the top of the central compartment about said outlet and connection, annular manifolds about said container at the bottom and top having branches connecting with the space between the container and liner, means for supplying temperature-control fluid to the bottom manifold, an external return circuit thereto from the top manifold, temperature-conditioning means in such circuit, reinforcing elements spaced about said container and secured to the top and bottom headers, and lagging between said reinforcing elements and the container.

2.- A fractional distillation apparatus, comprising a container, top and bottom headers therefor, \lin\er spaced within the container and forming central compartment, surface-providing filler means for liquid and vapor contact within the central compartment, a feed inlet to the central compartment below for material to be fractionated, and an outlet above for vapors, a connection for returning condensate from the condenser to the top of the central compartment, annular manifolds about said container at the bottom and top having branches connecting with the space between the container and liner, means for supplying temperature-control fluid to the bottom manifold, an external return circuit thereto from the top manifold, temperature-conditioning means in such circuit, reinforcing elements spaced about said container and secured to the top and bottom headers, and lagging between said reinforcing elements and the container.

. 3. A fractional distillation apparatus, comprising a container, top and bottom headers therefor, a liner spaced within the container and forming a central compartment, surface-providing filler means for liquid and vapor contact within the central compartment, a feed inlet to the central compartment below for material to be fractionated, and an outlet above for vapors, a connection for returning condensate from the condenser to the top of the central compartment, an insulating closure at the top of the central compartment about said outlet and the connection, annular manifolds about said container at the bottom and top having branches connecting with the space between the container and liner, means for supplying temperature-control fluid to the bottom manifold, an external return circuit thereto from the top manifold, temperature-conditioning means in such circuit, and reinforcing elements spaced about said container and secured to the top and bottom headers.

4. A fractional distillation apparatus, comprising a container, top and bottom headers therefor, a liner spaced within the container and forming a central compartment, surface-providing I aseaaee filler means for liquid and vapor contact within the central compartment. a feed inlet to the central compartment below for material to be fractionated, and an outlet above for vapors, a connection for returning condensate to the top of the central compartment, means including connections at the bottom and top for circulating temperature-control fluid to the space between the container wall and liner, reinforcing elements spaced about said container and secured to the top and bottom headers, and lagging between said reinforcing elements and the container.

5. A fractional distillation apparatus, comprising a container, top and bottom headers therefor,

a liner spaced within the container and forming a central compartment, surface-providing iliier means tor liquid and vapor contact Within the central compartment, a feed inlet to the central compartment below tor material to be fractionated, and an outlet above for vapors. a connection for returning condensate to the top 0! the cena trai compartment, an insulating closure at the top of the central compartment about said outlet and connection, and reinforcing elements spaced about said container and secured to the top and bottom headers.

ROBERT E. BURK.

' Patani; No. 2,585,515..

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Leslie Frazer (Seal) First Assistant comiasioner of Patents. 

